CLIAMS:1. An isolator configured to indicate true contact position, said isolator comprising:
a knob;
a torsional spring configured with the knob to function as a toggle spring and to define a toggle point;
a fixed contact; and
a moving contact assembly operatively coupled to the knob and configured to move and make a contact with the fixed contact, wherein the moving contact assembly comes in contact with the fixed contact after the toggle point is crossed.
2. The isolator of claim 1, wherein the knob and the moving contact assembly are operatively coupled to each other through a U-pin.
3. The isolator of claim 1, wherein the moving contact assembly incorporates a moving contact and a bridge.
4. The isolator of claim 3, wherein the moving contact assembly incorporates a compression spring between the moving contact and the bridge.
5. The isolator of claim 3, wherein the moving contact is connected to a terminal by a copper braid.
6. The isolator of claim 3, wherein the fixed contact and the moving contact incorporate a contact button each.
7. The isolator of claim 1, wherein the fixed contact is fixed on a terminal post.
8. The isolator of claim 1, wherein the fixed contact and the moving contact incorporate bends.
,TagSPECI:TECHNICAL FIELD
[0001] The present disclosure generally relates to the field of low voltage power systems. In particular, the present disclosure pertains to an isolator or switch disconnector that indicates true contact position.

BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art
[0003] Isolators or switch disconnectors are used in power/electrical circuits to ensure that the electrical circuit is completely de-energized as and when such necessity arises such as for service or maintenance. Such switches are often found in electrical distribution and industrial applications, where machinery must have its source of driving power removed for adjustment or repair. Thus they are designed to make, carry and break currents in power circuits in which they are configured. The current they carry may be normal operating current and at times specified operating overload currents for specific time or short circuit current for a specified time.
[0004] In general, a conventional isolation switch comprises of contact system and bar linkage mechanism. The bar linkage mechanism is used to actuate the double break butt-type contact system. As shown in FIG.1A, a typical bar linkage mechanism can consist of a knob 102 and a U-Pin 112. The contact system can include terminals 108, bridge assembly, and mechanism spring 114. The bridge assembly can include a bridge 104, a moving contact 110, and a compression spring 116. Both moving contact and the terminals can be configured with contact buttons 124. Knob 102 in the above described conventional isolator can have two rest positions - one corresponding to ‘OFF’ situation in which the moving contact 110 is away from the fixed contacts configured with the terminals 108 as shown in FIG. 1A and other corresponding to ‘ON’ situation in which the moving contact 110 is in contact with the contacts configured with the terminals 108 as shown in FIG. 1B.
[0005] The conventional isolators such as one described above suffer from certain limitations. In case the contact buttons of the moving contact and fixed contacts get welded due to any abnormal condition, the conventional isolator can develop an additional rest position in between ‘ON’ and ‘OFF’ positions. Thus even though the isolator is in ‘ON’ position, the knob would fail to indicate true position as shown in FIG.1C. This can lead to a wrong interpretation of the position of the isolator by a user and may lead to electric shock leading even to death of humans.
[0006] Further, as described above and shown in FIG. 1A. the conventional isolators have double break butt type contact system that require usage of four contact buttons, which results in to higher product cost. It would be advantageous if the number of contact buttons could be reduced to bare minimum to minimize the product cost.
[0007] There is therefore need in art for an isolator design that does not develop a third rest position for knob on welding of contacts, continues to show the true contact position i.e. ‘ON’ position on welding of contacts and reduces the number of contact buttons to reduce the product cost.
[0008] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
[0009] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term “about.” Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
[0010] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0011] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0012] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.

OBJECTS OF THE INVENTION
[0013] An object of the present disclosure is to overcome disadvantages associated with conventional isolators.
[0014] Another object of the present disclosure is to provide an isolator that is safe for users.
[0015] Another object of the present disclosure is to provide an isolator that shows the true position when the contact points get welded and thus ensures safety of user.
[0016] Another object of the present disclosure is to provide an isolator that is economical to produce.
[0017] Another object of the present disclosure is to provide an isolator design that minimizes the number of contact buttons and thus minimizes the product cost.
[0018] Another object of the present disclosure is to provide an isolator design that provides self arc blow-out system that effectively and quickly quenches arc.
[0019] Another object of the present disclosure is to provide an isolator design that can withstand high short circuit currents.

SUMMARY
[0020] Aspects of present disclosure relate to an isolator. In an aspect, the disclosed isolator overcomes deficiencies of the conventional isolators wherein, in the event of welding of contacts an additional rest point is created that inhibits indication of true position of the switch. In the disclosed isolator, no third rest point is generated in the event of welding of the contact points and the knob is prevented from moving out of its ‘ON’ position. Thus, the disclosed isolator continues to indicate ‘ON’ position in the event of welding of the contacts thus preventing wrong interpretation of the situation by user and consequent hazardous situation.
[0021] In an embodiment, the disclosure provides a design for isolator with a different arrangement of actuation linkages incorporating a torsional spring that acts as a toggle spring. The disclosed isolator can include a knob, a toggle spring, a bridge, a moving contact, and a fixed contact. The toggle spring can be connected to the knob directly with its other end fixed in the housing. The knob can be connected to the bridge through a U- pin. The moving contact assembly can be placed inside bridge and pivoted to move so as to make contact with the fixed contact.
[0022] In an embodiment, the toggle point of the toggle spring and knob arrangement is kept beyond the point where moving contact gets separated from fixed contact. In the event of welding of the moving contact and the fixed contact the two cannot get separated and therefore the actuation linkages cannot cross the toggle point making the linkages to go back to the ‘ON’ position under the force of the toggle spring. Thus, generation of an additional rest position is prevented and the knob returns to the ‘ON’ position when effort is made to move the knob out of its ‘ON’ position.
[0023] In an embodiment, the disclosure provides a design for isolator with a different contact system that includes only two contact buttons, thus reducing the number of buttons to two from four in the conventional isolator designs. This has been achieved by converting double break contact system used in conventional designs to a single break contact system. Reduction of contact points reduces the cost of the product making it cost effective both for consumer and manufacturer. Reduction in contact points also helps in prolonging the service life of the product as reduction in contact points that are susceptible to arcing/pitting/burning/welding, reduces the potential trouble spots in the product.
[0024] In an embodiment, the disclosed isolator incorporates features that provide high blowout force to push arc from contact buttons. A bend has been given into fixed contact to have higher forces with suitable inclination given to the moving contact.
[0025] In an embodiment, the disclosed isolator incorporates features that provide high short circuit current withstanding capability to the isolator. A compression spring is placed between moving contact and top surface of bridge to provide continuous force on moving contact to overcome repulsive or joint forces generated during occurrence of short circuit currents.
[0026] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components

BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[0028] FIG. 1A, 1B and 1C illustrate exemplary schematic views of internal details of a conventional isolator in “OFF”, “ON”, “Welded”conditions respectively.
[0029] FIG. 2A, 2B and 2C illustrate exemplary schematic views of internal details of disclosed isolator in “OFF”, “ON”, “Welded”” conditions respectively in accordance with embodiments of the present disclosure.
[0030] FIG. 3A, 3B and 3C illustrate exemplary line diagrams of actuation linkages and contact system in “OFF”, “Toggle point”, “ON” positions respectively in accordance with embodiments of the present disclosure.
[0031] FIG. 4 illustrates an exemplary schematic view of terminal assembly in accordance with embodiments of the present disclosure.
[0032] FIG. 5 illustrates an exemplary schematic view of moving contact assembly in accordance with embodiments of the present disclosure.

DETAILED DESCRIPTION
[0033] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0034] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the “invention” may in some cases refer to certain specific embodiments only. In other cases it will be recognized that references to the “invention” will refer to subject matter recited in one or more, but not necessarily all, of the claims.
[0035] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0036] All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0037] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.
[0038] Embodiments of the present disclosure relate to an isolator. In an aspect the disclosed isolator overcomes deficiencies of the conventional isolators wherein, in the event of welding of contacts an additional rest point is created that inhibits indication of true position of the switch. As illustrated in FIG. 1C the knob tends to take a third position in the event of welding of contact points. In the disclosed isolator no third rest point is generated in the event of welding of the contact points and the knob is prevented from moving out of its ‘ON’ position. Thus the disclosed isolator continues to indicate ‘ON’ position in the event of welding of the contacts thus preventing wrong interpretation of the situation by user and consequent hazardous situation.
[0039] In an embodiment, the disclosure provides a design for isolator with a different arrangement of actuation linkages incorporating a torsional spring that acts as a toggle spring. The disclosed isolator can comprise a knob, a toggle spring, a bridge, a moving contact assembly and a fixed contact. The toggle spring can be connected to the knob directly with its other end fixed in the housing. The knob can be connected to the bridge through a U- pin. The moving contact assembly can be placed inside bridge and pivoted to move so as to make contact with the fixed contact.
[0040] In an embodiment, the toggle point of the toggle spring and knob arrangement is kept beyond the point where moving contact gets separated from fixed contact. In the event of welding of the moving contact and the fixed contact the two cannot get separated and therefore the actuation linkages cannot cross the toggle point making the linkages to go back to the ‘ON’ position under the force of the toggle spring. Thus generation of an additional rest position is prevented and the knob returns to the ‘ON’ position when effort is made to move the knob out of its ‘ON’ position.
[0041] In an embodiment, the disclosure provides a design for isolator with a different contact system that comprises only two contact buttons thus reducing the number of buttons to two from four in the conventional isolator designs. This has been achieved by converting double break contact system used in conventional designs to a single break contact system. Reduction of contact points reduces the cost of the product making it cost effective both for consumer and manufacturer. Reduction in contact points also helps in prolonging the service life of the product as reduction in contact points that are susceptible to arcing/pitting/burning/welding, reduces the potential trouble spots in the product.
[0042] In an embodiment, the disclosed isolator incorporates features that provide high blowout force to push arc from contact buttons. A bend has been given into fixed contact to have higher forces with suitable inclination given to the moving contact.
[0043] In an embodiment, the disclosed isolator incorporates features that provide high short circuit current withstanding capability to the isolator. A compression spring is placed between moving contact and top surface of bridge to provide continuous force on moving contact to overcome repulsive or joint forces generated during occurrence of short circuit currents.
[0044] Referring now to FIG. 2A, an exemplary schematic view 200 of internal details of disclosed isolator is disclosed in accordance with embodiments of the present disclosure. As shown in the exemplary schematic view 100, the disclosed isolator can include a knob 202, a toggle spring 204, a bridge 206, a moving contact 208 and a fixed contact 210. The toggle spring 204 can be connected to the knob 202 directly with its other end fixed in the housing. The knob 202 can be connected to the bridge 206 through a U- pin 212. The moving contact 208 can be placed inside bridge 206 and pivoted to move so as to make contact with the fixed contact 210. A flexible copper braid 216 can provide electrical connection between moving contact 208 and terminal 214.
[0045] The view 200 of FIG. 2A illustrates arrangement of actuation mechanism and contact system in ‘OFF’ position of the isolator wherein the two contacts are separated from each other. The knob 202 is in its first rest position under force of the toggle spring 204. During operation, when the knob 202 is rotated, it can drive the bridge 206 and the torsion spring 204. The torsion spring 204 will get compressed till toggle point after which it can release its stored energy to drive moving contact 208 making it independent and move on to make a contact with the fixed contact 210 completing the current path. At this stage, switch is in ON position as illustrated in FIG. 2B and corresponding position of knob is its second rest position corresponding to ON state.
[0046] FIG. 2C illustrates the exemplary schematic view of internal details of disclosed isolator in “Welded” conditions in accordance with an embodiment of the present disclosure. In an embodiment, the toggle point of the toggle spring 204 and knob 202 is kept before the point where moving contact 208 gets in contact with fixed contact 210 when the knob 202 is being moved from its first rest position to the second rest position. Therefore, when the knob 202 is rotated from its second rest position to its first rest position, the toggle point of the toggle spring 204 and the knob 202 is beyond the separation point of the two contacts. In the event of welding of the moving contact 208 and the fixed contact 210 the two cannot get separated and therefore the actuation linkages cannot cross the toggle point making the linkages to go back to the ‘ON’ position under the force of the toggle spring. Thus generation of an additional rest position is prevented and the knob returns to the ‘ON’ position when effort is made to move the knob out of its ‘ON’ position.
[0047] FIG. 3A, 3B and 3C illustrate exemplary line diagrams 300, 330 and 360 of actuation linkages and contact system in “OFF”, “Toggle point”, “ON” positions respectively in accordance with embodiments of the present disclosure. In line diagrams 300, point 302 is center of the knob 202, points 304 and 306 are two ends of U- pin 212. Points 306, 308 represent two ends of the bridge 206 and 310 & 312 are moving contact and fixed contacts respectively. One end 314 of the toggle spring 204 can be fixed to housing and other end 316 to the knob 202. The view 300 of FIG. 3A shows the position of linkages and contact system in their first rest position that corresponds to the ‘OFF’ condition of the isolator. As the knob is shifted from its rest position to move to the second rest position that corresponds to ‘ON’ condition of the isolator, the movement compresses the toggle spring 204 up to a certain point corresponding to toggle point of the knob 202 and toggle spring 204 arrangement. Thereafter, the spring 204 can release its stored energy to drive moving contact 208 making it independent and move on to make a contact with the fixed contact 210 completing the current path.
[0048] FIG. 3B illustrates an exemplary line diagram 330 of actuation linkages and contact system in “Toggle point” position in accordance with embodiments of the present disclosure. As shown, at this point the moving contact 208 is yet to make a contact with the fixed contact 210.
[0049] FIG. 3C illustrates an exemplary line diagram 360 of actuation linkages and contact system in “ON” position in accordance with embodiments of the present disclosure. The knob 202 is in its second rest position here and the position corresponds to ‘ON’ condition of the isolator. If the contact points were to get welded in this condition and an effort was made to shift the knob 202 out of this position, the actuating mechanism shall fail to cross the toggle point as the welded contacts shall prevent any such effort. Therefore, the knob shall return back to its second rest position under the force of the toggle spring 204. Thus, the knob 202 shall remain in position that corresponds to ‘ON’ condition of the isolator depicting its true position.
[0050] FIG. 4 illustrates an exemplary schematic view of terminal assembly in accordance with embodiments of the present disclosure. The terminal assembly can comprise the fixed contact 210 that incorporates a contact button 124, terminal block 402 and a screw 404. In an embodiment, the arrangement of terminal 500 and moving contact 208 have high blowout force. A bend has been incorporated in the fixed contact 210 to have higher forces with suitable inclination given onto moving contact 208.
[0051] FIG. 5 illustrates an exemplary schematic view of moving contact assembly 500 in accordance with embodiments of the present disclosure. The moving contact assembly 500 can include the moving contact 208 that incorporates a contact button 124, pivoting block 502 and bridge 206. The bridge 206 can have a hole 504 for assembly of U- pin 112 that connects the bridge 206 to the knob 202. There can be compression spring 506 configured between the moving contact 208 and top surface of the bridge 206. The compression spring 506 ensures a continuous force on moving contact 208 to overcome repulsive or joint forces, thus ensuring that the isolator can withstand high short circuit currents. The moving contact 208 also incorporates a bend matching the bend in the fixed contact.
[0052] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF THE INVENTION
[0053] The present disclosure overcomes disadvantages associated with conventional isolators.
[0054] The present disclosure provides an isolator that is safe for users.
[0055] The present disclosure provides an isolator that shows the true position when the contact points get welded and thus ensures safety of user.
[0056] The present disclosure provides an isolator that is economical to produce.
[0057] The present disclosure provides an isolator design that minimizes the number of contact buttons and thus minimizes the product cost.
[0058] The present disclosure provides an isolator design that provides self arc blow-out system that effectively and quickly quenches arc.
[0059] The present disclosure provides an isolator design that can withstand high short circuit currents.